diff --git a/day11/prod.in.txt b/day11/prod.in.txt
new file mode 100644
index 0000000..2e2bd25
--- /dev/null
+++ b/day11/prod.in.txt
@@ -0,0 +1,55 @@
+Monkey 0:
+  Starting items: 50, 70, 89, 75, 66, 66
+  Operation: new = old * 5
+  Test: divisible by 2
+    If true: throw to monkey 2
+    If false: throw to monkey 1
+
+Monkey 1:
+  Starting items: 85
+  Operation: new = old * old
+  Test: divisible by 7
+    If true: throw to monkey 3
+    If false: throw to monkey 6
+
+Monkey 2:
+  Starting items: 66, 51, 71, 76, 58, 55, 58, 60
+  Operation: new = old + 1
+  Test: divisible by 13
+    If true: throw to monkey 1
+    If false: throw to monkey 3
+
+Monkey 3:
+  Starting items: 79, 52, 55, 51
+  Operation: new = old + 6
+  Test: divisible by 3
+    If true: throw to monkey 6
+    If false: throw to monkey 4
+
+Monkey 4:
+  Starting items: 69, 92
+  Operation: new = old * 17
+  Test: divisible by 19
+    If true: throw to monkey 7
+    If false: throw to monkey 5
+
+Monkey 5:
+  Starting items: 71, 76, 73, 98, 67, 79, 99
+  Operation: new = old + 8
+  Test: divisible by 5
+    If true: throw to monkey 0
+    If false: throw to monkey 2
+
+Monkey 6:
+  Starting items: 82, 76, 69, 69, 57
+  Operation: new = old + 7
+  Test: divisible by 11
+    If true: throw to monkey 7
+    If false: throw to monkey 4
+
+Monkey 7:
+  Starting items: 65, 79, 86
+  Operation: new = old + 5
+  Test: divisible by 17
+    If true: throw to monkey 5
+    If false: throw to monkey 0
diff --git a/day11/solution.go b/day11/solution.go
new file mode 100644
index 0000000..e1baf78
--- /dev/null
+++ b/day11/solution.go
@@ -0,0 +1,164 @@
+package day11
+
+import (
+	"fmt"
+	"sort"
+	"strconv"
+	"strings"
+)
+
+type Solver struct {
+	monkeys []*MonkeySpec
+}
+
+type MonkeySpec struct {
+	itemWorryLevels         []uint64
+	advancedItemWorryLevels []ItemWorryLevel
+	opType                  string
+	opValue                 uint64
+	testDivisor             uint64
+	targetMonkeyIfTrue      int
+	targetMonkeyIfFalse     int
+	numInspections          int
+}
+
+type ItemWorryLevel struct {
+	multipliers []uint64
+	additive    uint64
+}
+
+func (i *ItemWorryLevel) Value() uint64 {
+	v := uint64(1)
+	for _, m := range i.multipliers {
+		v *= m
+	}
+	return v + i.additive
+}
+
+func (i *ItemWorryLevel) Mod(d uint64) uint64 {
+	currentDivisor := uint64(1)
+	for _, m := range i.multipliers {
+		currentDivisor *= m % d
+	}
+	currentDivisor += i.additive
+	currentDivisor %= d
+
+	return currentDivisor
+}
+
+func (i *ItemWorryLevel) TimesConst(c uint64) *ItemWorryLevel {
+	r := *i
+	r.multipliers = append(r.multipliers, c)
+	r.additive *= c
+	return &r
+}
+
+// func (i *ItemWorryLevel) Squared() *ItemWorryLevel {
+// 	r := *i
+// 	r.multipliers = append(r.multipliers, (2*i.additive)%allDivisors)
+// 	r.multipliers = append(r.multipliers, i.multipliers...)
+// 	r.additive *= i.additive
+// 	return &r
+// }
+
+func (s *Solver) ParseInput(input []string) {
+	s.monkeys = make([]*MonkeySpec, 1+len(input)/7)
+	for m := 0; m < len(s.monkeys); m++ {
+		offset := 7 * m
+
+		startingItemsLine := strings.Split(strings.Split(input[offset+1], ": ")[1], ", ")
+		startingItems := make([]uint64, len(startingItemsLine))
+		advancedStartingItems := make([]ItemWorryLevel, len(startingItemsLine))
+		for i, item := range startingItemsLine {
+			startingItems[i], _ = strconv.ParseUint(item, 10, 64)
+			advancedStartingItems[i] = ItemWorryLevel{[]uint64{startingItems[i]}, 0}
+		}
+
+		operationLine := strings.Split(strings.Split(input[offset+2], " old ")[1], " ")
+		opType := operationLine[0]
+		opValue, _ := strconv.ParseUint(operationLine[1], 10, 64)
+
+		divisor, _ := strconv.ParseUint(strings.Split(input[offset+3], " by ")[1], 10, 64)
+
+		trueTargetMonkey, _ := strconv.Atoi(strings.Split(input[offset+4], " monkey ")[1])
+		falseTargetMonkey, _ := strconv.Atoi(strings.Split(input[offset+5], " monkey ")[1])
+
+		s.monkeys[m] = &MonkeySpec{
+			itemWorryLevels:         startingItems,
+			advancedItemWorryLevels: advancedStartingItems,
+			opType:                  opType,
+			opValue:                 opValue,
+			testDivisor:             divisor,
+			targetMonkeyIfTrue:      trueTargetMonkey,
+			targetMonkeyIfFalse:     falseTargetMonkey,
+		}
+	}
+}
+
+func (s *Solver) SolvePart1() any {
+	return s.solve(20, true)
+}
+
+func (s *Solver) SolvePart2() any {
+	return s.solve(10000, false)
+}
+
+func (s *Solver) solve(numberOfRounds uint64, divideByThree bool) any {
+	allDivisors := uint64(1)
+	for _, d := range s.monkeys {
+		allDivisors *= d.testDivisor
+	}
+
+	for r := 0; r < int(numberOfRounds); r++ {
+		for _, monkey := range s.monkeys {
+			for _, item := range monkey.itemWorryLevels {
+				monkey.numInspections++
+
+				newWorryLevel := item
+				var opValue uint64
+				if monkey.opValue == 0 {
+					opValue = item
+				} else {
+					opValue = monkey.opValue
+				}
+				switch monkey.opType {
+				case "*":
+					newWorryLevel *= opValue
+				case "+":
+					newWorryLevel += opValue
+				}
+				if divideByThree {
+					newWorryLevel /= 3
+				} else {
+					newWorryLevel %= allDivisors
+				}
+
+				var targetMonkey int
+				if newWorryLevel%monkey.testDivisor == 0 {
+					targetMonkey = monkey.targetMonkeyIfTrue
+				} else {
+					targetMonkey = monkey.targetMonkeyIfFalse
+				}
+				s.monkeys[targetMonkey].itemWorryLevels = append(s.monkeys[targetMonkey].itemWorryLevels, newWorryLevel)
+				// fmt.Printf("-> Throwing to monkey: %d\n", targetMonkey)
+			}
+			monkey.itemWorryLevels = []uint64{}
+		}
+		// fmt.Printf("\nround %d:\n", r)
+		// s.printMonkeys()
+	}
+
+	var numInspections []int
+	for _, m := range s.monkeys {
+		numInspections = append(numInspections, m.numInspections)
+	}
+	sort.Ints(numInspections)
+
+	return uint64(numInspections[len(numInspections)-1]) * uint64(numInspections[len(numInspections)-2])
+}
+
+func (s *Solver) printMonkeys() {
+	for _, m := range s.monkeys {
+		fmt.Printf("%+v\n", m)
+	}
+}
diff --git a/day11/test.in.txt b/day11/test.in.txt
new file mode 100644
index 0000000..c04eddb
--- /dev/null
+++ b/day11/test.in.txt
@@ -0,0 +1,27 @@
+Monkey 0:
+  Starting items: 79, 98
+  Operation: new = old * 19
+  Test: divisible by 23
+    If true: throw to monkey 2
+    If false: throw to monkey 3
+
+Monkey 1:
+  Starting items: 54, 65, 75, 74
+  Operation: new = old + 6
+  Test: divisible by 19
+    If true: throw to monkey 2
+    If false: throw to monkey 0
+
+Monkey 2:
+  Starting items: 79, 60, 97
+  Operation: new = old * old
+  Test: divisible by 13
+    If true: throw to monkey 1
+    If false: throw to monkey 3
+
+Monkey 3:
+  Starting items: 74
+  Operation: new = old + 3
+  Test: divisible by 17
+    If true: throw to monkey 0
+    If false: throw to monkey 1
\ No newline at end of file
diff --git a/main.go b/main.go
index 07cf341..15a6e42 100644
--- a/main.go
+++ b/main.go
@@ -16,6 +16,7 @@ import (
 	"snikolov.me/aoc2022/day08"
 	"snikolov.me/aoc2022/day09"
 	"snikolov.me/aoc2022/day10"
+	"snikolov.me/aoc2022/day11"
 
 	"snikolov.me/aoc2022/utils"
 )
@@ -60,6 +61,7 @@ func solve(args Args, inputFileName string) {
 		8:  &day08.Solver{},
 		9:  &day09.Solver{},
 		10: &day10.Solver{},
+		11: &day11.Solver{},
 	}
 	solver, ok := solvers[args.DayNumber]
 	if !ok {